This is the knob that controls the seat position adjusting latch for the center seats of a Piper Aztec-F airplane. May fit other models, I don't know. This is Piper part no. 571-165.

The design is not exact as I did not reproduce the beveled edges. That seemed to be the point of diminishing returns. The difference isn't all that noticeable and has no effect on functionality. Feel free to add that.

This probably will never be a top-ten Thing, but these knobs are absolutely impossible to find anymore. This part was discontinued by Piper many years ago.